The governments of Western Europe, Russia and China will realize that a nuclear Iran represents a threat to them, rather than being a customer for their armaments industry and a stumbling block for the U.S. The air forces of the EU, launched from bases in Turkey, with assistance from aircraft from Russian and Chinese carriers in the Arabian Gulf will take out Iranian nuclear assets without collateral damage or civilian casualties.

Or nothing at all will happen.

Put me down for nothing happens. China could care less, Russia never stopped fighting the Cold War, and Western Europe is stuck in the duel mire of self-interest and love of unending diplomacy.

Unless Israel decides to make a move at some point, nothing will happen and Iran will field a nuclear arsenal. And Hezbollah may end up with a nuclear weapon to shake (or worse) at Israel within the next decade.

If Iran does develop a nuclear weapon and the ability to deliver it (still a few years off), they are not going to hand it to Hezbollah. Nations do not spend billions of dollars on developing nuclear weapons and just hand them off to another party. They get them to prevent invasions. Iran saw what happened to Iraq, and what did not happen to North Korea, and quite rationally thought they had to get nukes right away. That they don't trust the Arabs either only adds to their desire for a nuke.

For all the fanaticsm of the mullahs in Iran, Iran has not launched a conventional war against its neighbors. But sponsoring Hamas and Hezbollah is not that different from when Israel sponsored Christian militias in Lebanon in the 1980s. Why undertake hostilities yourself when you can send proxies?

The risk to the West is that Iran steps up that support, safely behind a nuclear shield. This is the case between India and Pakistan, where Islamabad can raise and lower their support for terrorist groups, and limit India's retaliation.